You're not gonna believe me, especially after this article, but Japanese is actually not as hard to learn as everybody thinks it is. This makes it the ideal field of study for people who want to appear smart with minimal effort at the expense of never finding a related job. That said, there may be a few things about the language that are a teensy bit way more complicated than necessary.
Alright, so you've started learning a new language. Good job. One of the first things you'll want to do is learn how to count stuff. Fair enough, just memorize the words for the numbers and you're set, right? Whoa now, slow down there, sport! In Japanese, if you want to say how many of something there are - let's say the number of girls you've been turned down by, for example - you can't just say "307" or someone might reply in the condescending voice of your 2nd grade teacher and ask, "307 what, Ryan?" Of course, it should be obvious that you're talking about 307 girls, but you need to actually go out of your way to indicate that. It turns out that there are suffixes you need to add to the number according to what it is you're counting. For example, for people, add "nin", for flat objects, add "mai", and for glasses of drink (or octopi, for some reason), add "hai". Not only are there literally bazillions (I counted) of different counters to memorize, they sometimes change a bit when you add them or are entirely different for certain numbers. Basically, if you need to quantify something in Japanese, you're better off grunting and communicating with eyebrow gestures.
Being Polite (or not)
Ok, so maybe now you've gotten some more Japanese under your tightly fitting belt and you're thinking "Gee willikers, Japanese verb conjugation is actually way easier than it is in stuff like Spanish." Well you'd be right. In Japanese, you don't have to change the verb based on who the subject is and you can just use the same forms from present tense for future tense. It's stupidly simple. But don't worry, all you fans of mind-numbing memorization, Japanese still has plenty of conjugations for you to flood your mind with, they're just hidden where you'd never think to look: in polite conversations. I can tell you from experience that most Japanese people are annoyingly polite (or more clever and roundabout in their impoliteness). The language reflects that cultural focus on politeness by having whole new forms of verbs depending on whether you're talking to your boss, your sister, or your yakuza cohorts. Sometimes it's as easy as learning another verb ending, but many times you'll use an entirely different word that means the same thing, but which is more (or less) polite. So as an example, if you want to tell your boss to go rot in the depths of the underworld, you should be sure to use "irassharu" for "go" instead of "iku". You wouldn't want to be rude, after all.
Reading and Writing
I'm pretty sure the Japanese writing system is the entire reason that everyone thinks the language is impossible to learn. They see some scribbles, think "I can't understand that", and then give up and return to their coloring books. On the bright side, you don't have to worry about getting hooked on phonics to memorize all the rules and exceptions of pronunciation like you would if you were learning English as a second language. Japanese has hardly any sounds and they're all pronounced the same way every time. You can even write out words phonetically using Hiragana and Katakana. You can write them that way, but you wouldn't unless you're a kindergartner or an idiot. Instead you'll be using those two alphabets of 46 characters each in combination with the imported Chinese characters called kanji of which there are 6,000ish in modern use. But don't worry, even though learning each kanji is harder than memorizing the random configuration of a pile of dropped chopsticks while blindfolded, you really only need to know closer to 2,000 to get by in everyday situations.
But apart from those three things, Japanese is a piece of cake. Really. You'll be watching your Dragon Balls and playing imported video games by noon tomorrow.